<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>2-7</title>
		<style>
			.div2{
				float:left;
				border:1px solid blue;
				width:40px;
				height:20px;
			}
			.div3{
				clear:both;
				border:1px solid green;
				width:200px;
				height:80px;
			}
		</style>
	</head>
	<body>
		<div style="border:1px solid red;height:80px;width:200px;">div1</div>
		<div class="div2">div2</div>
		<div class="div2">div2</div>
		<div class="div2">div2</div>
		<div class="div2">div2</div>
		<div class="div3">div3</div>
	</body>
</html>
